Sudden Short Story 108

The girl unexpectedly hugged the boy, who himself pretended to be a girl, and he giggled at the jest. 
"What's this for?" he asked. 
She leaned in close and whispered, "I figured out that you're a boy." 
His first reaction was to jump away, but she held him tight. 
"I can't be a boy," he pleaded.  "Boys are mean, and I'm not mean." 
"I figured it out, though," she said.  "There's something about you that seems different, something that I like....  I realized it after I drank from the fountain of wisdom." 
He struggled with her, but she just held on tight.  "The fountain of wisdom is corrupted and broken," he said, "No one's supposed to drink from it!" 
"And I wanted to know why," she said.  "It all made so much sense afterward, too.  We live forever because we drink from the fountain of youth, but we've forgotten more than we can remember.  Even I don't know where everyone went, and I don't intend to find out.  The grown-ups have been gone for a very long time, and so have the boys.
"But," she whispered again, "now I have a boy of my very own."
And he wondered if she would ever let him go.